Mini medical pump design provides accurate dosage

May 8, 2008 Researchers at the Fraunhofer Institute in Germany have developed an innovative mini peristaltic pump system to accurately administer tiny quantities of liquid such as medicines. What sets this pump apart from standard micro-pumps is its low-maintenance operation and the flexibility of working in both directions that it offers.

The problems associated with most micro-pump systems is that they work only in one direction, bubbles can appear in the liquid that impair their operation, they do not tolerate small particles, have a fixed pump output and moving parts such as valves or cogwheels. The controllable peristaltic micro-pump from the researchers at Fraunhofer addresses these issues as it contracts in waves in a similar way to the human esophagus, changes shape as needed and propelling the liquid along.

The researchers created the pump using lead-zirconate-titanate (PZT) films that are joined in a suitable way with bending elements made of carbon-fiber-reinforced plastic and a flexible tube. These materials change their shape via the application of an electric field enabling tiny quantities (just a few tenths of a milliliter) to be pumped accurately through the system.

The system has passed its first functional tests and is now being adapted to different applications.